Efficient Dynamics - problems and inconveneinces

Hello, I am a student and I am currently doing a project about the Efficient Dynamics (BMW) and in general start stop function in cars. We are very much interested in finding problems and inconveniences that users have with such a system. Did you encounter any problems or have inconveniences that you would like to have solved in the future regarding this system? It would be of great help for my project. Thank you in advance!